There is a known heat exchanger comprising a tube and a wire ribbing attached to it, in which the wire after expedient deformation is folded to a concertina-like shape, and then attached to the mantle of the tube along one of its generatrices by a permanent joint, e.g. welding or soldering. Such a heat exchanger is described in the Hungarian Pat. No. 153,573.
A lamellar cooling ribbing is known furthermore from the Hungarian Pat. No. 144,706, where a metal strip folded in a zigzag shape is inserted between two cooling tubes, and where the metal strip constitutes the cooling ribbing.
In both of the above mentioned devices the ribs are of a continuous material and their surfaces stand in the direction of flow of the medium streaming at a right angle to the tube axis. Heat exchangers of this type have the advantage that their production can easily be automated, and that they can be produced in a welded construction as well, i.e. they can be used even in cases of high temperature.